Prior art which is related to this technical field can e.g. be found in specifications describing analog baseband filters.
The following meanings for the abbreviations used in this specification apply:
HSDPA: High Speed Downlink Packet Access
LTE: Long Term Evolution
LTE-A: LTE-Advanced
TI: Transferred Impedance
TIF: Transferred Impedance Filter
TIS: Transferred Impedance Structure
WCDMA: Wideband Code Division Multiple Access
The analog baseband filter in a receiver is required to suppress unwanted signal components before analog-to-digital conversion.
For example, in a transceiver, a transmit signal is generated at a sufficiently high power level for transmission. Thus, a part of the transmit signal can leak into a receive path due to an unwanted coupling mechanism, resulting, in an unwanted signal component known as “transmit leakage”. The unwanted coupling mechanism may be caused by finite attenuation of a duplex filter or parasitic coupling between lines on a printed wiring board, for example. The transmit leakage is processed by the receive path, and appears at the input of an analog-to-digital converter at a frequency offset relative to the wanted signal component. Depending on the frequency offset and the analog-to-digital converter conversion rate, the transmit leakage may result in an alias component being created by the analog-to-digital converter.